bug in ASN1_time_parse(3)

[Olivier Taïbi]

I think there is a bug in ASN1_time_parse(3): if tm is not NULL then it
is not zero'd before parsing and the year value is added instead of set.

diff --git a/lib/libcrypto/asn1/a_time_tm.c b/lib/libcrypto/asn1/a_time_tm.c
index b6e22cbd27b..a841f32a856 100644
--- a/lib/libcrypto/asn1/a_time_tm.c
+++ b/lib/libcrypto/asn1/a_time_tm.c
@@ -196,7 +196,7 @@ ASN1_time_parse(const char *bytes, size_t len, struct tm 
*tm, int mode)
                                return (-1);
                        type = V_ASN1_UTCTIME;
                }
-               lt->tm_year += ATOI2(p);                /* yy */
+               lt->tm_year = ATOI2(p);                 /* yy */
                if (type == V_ASN1_UTCTIME) {
                        if (lt->tm_year < 50)
                                lt->tm_year += 100;